CN116024565A - Laser cladding repair equipment for gear tooth surface fatigue crack - Google Patents

Abstract

The utility model relates to a gear tooth face fatigue crack's laser cladding repair equipment utilizes control system real-time detection fatigue crack's shape, has adopted different laser processing parameters respectively to the straightway of fatigue crack, curve section, especially to the curve section of fatigue crack with single laser beam replace two bundles of laser beams, has effectively guaranteed the welding quality of whole fatigue crack, and fatigue crack welding efficiency is high, cladding regional grain structure is even, has effectively improved the whole repair quality of fatigue crack.

Description

Laser cladding repair equipment for gear tooth surface fatigue cracks

technical field

The invention belongs to the field of laser repair, and more specifically relates to a laser cladding repair device for fatigue cracks on gear tooth surfaces.

Background technique

Gears are an important part of mechanical transmission systems. Continuous operation under high-speed or high-load conditions will cause gear failure and damage. The failure and damage forms of gears are determined by various factors such as their lubrication conditions, working conditions, parts materials, heat treatment methods adopted in the manufacturing process, and the manufacturing and installation process of parts. The failure of gears can generally be divided into two categories: tooth body damage and tooth surface damage. Tooth body damage is the tooth breakage, and tooth surface damage includes four methods: plastic deformation of the teeth, tooth surface gluing, wear and tooth surface fatigue. .

Tooth surface fatigue is a relatively common situation of tooth surface damage. Since the equivalent stress on the tooth surface of the gear changes, when the bearing capacity on the tooth surface is greater than the alternating equivalent stress on the tooth surface material, it will last for a long time Fatigue cracks will occur at this location. For some equipment with precise structure and high manufacturing cost, direct replacement will cause greater economic loss. For example, the production cost of high-precision gears and generator gears is relatively high. Direct replacement of failed gears will lead to high cost, while repairing can significantly reduce maintenance costs. The current repair processes on the market usually include methods such as spraying, electroplating, chemical plating, and laser cladding. As an emerging surface modification technology, laser cladding is the most widely used in gear repair. Compared with traditional repair methods, laser cladding has the advantages of small heat-affected zone and high metallurgical bonding. Based on the fatigue cracks that appear on the gear tooth surface in the actual production process, they are usually irregular in shape, and appear in the form of curves, corners and other shapes. During the cladding process, the convection, heat transfer, and mass transfer of the liquid in the molten pool are affected by the temperature field, which affects the solidification and composition uniformity of the liquid metal in the molten pool, which in turn affects the surface quality of the cladding layer. decisive influence. However, in the prior art, there is no matching laser processing technology for the shape of the fatigue crack, and generally only a single laser processing mode is used to incident the area to be repaired.

Since the actual fatigue crack is irregular, when the laser is incident on the fatigue crack curve segment, the laser scanning rate at the curve or corner is slow, if the same laser processing technology as the straight line segment is still used, the laser heat source and scanning rate will be Therefore, adjusting the appropriate laser spot and laser power according to the actual fatigue crack shape to improve the repair quality is an important problem that needs to be solved urgently.

Contents of the invention

The invention relates to a laser cladding repair equipment for gear tooth surface fatigue cracks, which aims to solve the phenomenon of overburning of the laser cladding welding seam and coarse grains of the gear tooth surface fatigue cracks in the prior art, resulting in low repair quality. question.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A laser cladding repair equipment for gear tooth surface fatigue cracks, characterized in that: the fatigue cracks are basically straight and curved sections, and the laser cladding repair equipment includes:

A laser transmitter and a control system, the laser transmitter emits a first wavelength laser and a second wavelength laser, and the control system controls the independent switch of the first wavelength laser and the second wavelength laser in the laser transmitter; the second A multi-functional lens is arranged on the optical path of the first-wavelength laser and the second-wavelength laser, and the surface of the multi-functional lens is coated with a film layer. The first-wavelength laser passes through the multi-functional lens and emits vertically downward. The second wavelength laser beam is split into two split laser beams with the same energy after passing through the multifunctional lens, one split laser beam is emitted vertically downward through the multifunctional lens, and the other split laser beam is emitted vertically downward after passing through the reflector, The one split laser beam and the other split laser beam are arranged and distributed along the length direction of the fatigue crack; it also includes a powder feeding channel arranged obliquely, the powder feeding channel forms an angle α with the vertical direction, and the powder feeding channel is pneumatic Send powder.

Further, a first linear light shaping unit, a second linear light shaping unit, and a third linear light shaping unit are independently arranged below the first wavelength laser beam, a split laser beam, and another split laser beam that emerge vertically. , the first linear light shaping unit, the second linear light shaping unit, and the third linear light shaping unit are all connected to the displacement driving system, the displacement driving system is connected to the control system, and the displacement driving control system is used to control the first linear light shaping unit, the second linear light shaping unit, and the horizontal movement of the third linear light shaping unit.

Further, a repair process of laser cladding repair equipment for gear tooth surface fatigue cracks, the repair process includes the following steps;

Step 1), the control system obtains the curvature of the fatigue crack on the gear tooth surface to be repaired, and when the control system detects that the current shape of the fatigue crack is basically a straight line segment, the laser emitter emits a laser beam of the first wavelength, and the laser power 1800W-2100W, the first wavelength laser beam is incident on the straight line of the fatigue crack;

Step 2), the control system detects the curvature of the fatigue crack in real time, and when the control system detects that the current shape of the fatigue crack is a curve segment, the laser processing technology is selected based on the database to match the curvature of the current curve segment, and the laser transmitter turns off the first A laser beam of one wavelength emits a laser beam of a second wavelength at the same time, and the laser beam of the second wavelength is split into exactly the same one split laser beam and another split laser beam after passing through a multifunctional lens coated with a film layer, and one split laser beam and another split laser beam The laser power of the split laser beam is 1500-1700W, and the one split laser beam and the other split laser beam are incident on the fatigue crack curve segment;

Step 3), when the control system 2 detects that the current shape of the fatigue crack returns to a substantially straight line segment, the laser emitter turns off the second wavelength laser beam and emits the first wavelength laser beam at the same time, the laser power is 1800-2100W, and the first wavelength laser beam The beam is incident on the straight line segment of the fatigue crack;

Wherein, the database in step 2) realizes the integrated construction of welding process data through pre-offline modeling, and different curvatures of fatigue cracks correspond to different laser powers, laser spots, laser scanning speeds and powder feeding rates.

Further, the laser transmitter is a fiber laser, the gear material is No. 45 carbon structural steel, and the material of the alloy powder of the cladding layer includes C, Cr, B, Si, Ni, Fe, and the content of Fe is not less than 80%.

Further, in the step 1) and step 3), the laser defocus is 0 to -20mm, the laser scanning rate is 300-600mm/min, the powder feeding rate is 30-50g/min, and the included angle α is 30° -60°.

In step 2), the laser defocus is 0 to -20mm, the laser scanning rate is 240-480mm/min, the powder feeding rate is 24-40g/min, and the included angle α is 30°-60°.

Further, in step 1) and step 3), before the laser emitter emits the laser beam of the first wavelength, the control system controls the first linear light shaping unit to move horizontally out of the optical path; in step 2), before the laser emitter emits the laser beam of the second wavelength Before the laser beam, the control system controls the second linear light shaping unit and the third linear light shaping unit to move out of the optical path horizontally; in the steps 1) and 3), the light spot of the first wavelength laser incident on the straight line segment of the fatigue crack is Gaussian Laser spot A, the laser spot A is circular, with a diameter of 2-3mm; the second wavelength laser in the step 2) is a Gaussian laser beam, and the split laser beam and the other split laser beam The spot where the laser beam is incident on the fatigue crack curve section is a Gaussian laser spot B, and the laser spot B is circular in shape with a diameter of 1.8-2.7 mm.

According to another embodiment of the present invention, in step 1) and step 3), before the laser emitter emits the laser beam of the first wavelength, the control system controls the first linear light shaping unit to move horizontally out of the optical path; in step 2), before the laser emitter Before the laser beam of the second wavelength is emitted by the control system, the second linear light shaping unit and the third linear light shaping unit are horizontally moved into the optical path; the first wavelength laser is incident on the straight line segment of the fatigue crack in the steps 1) and 3). The spot above is a Gaussian laser spot, and the laser spot A is circular with a diameter of 2-3mm; the second wavelength laser in the step 2) is a Gaussian laser beam, and the first split laser beam passes through the second linear The light shaping unit is modulated into a rectangular spot C incident on the fatigue crack curve segment, and the other split laser beam is also modulated into a rectangular spot C incident on the fatigue crack curve segment by the third linear light shaping unit. The width of C in the fatigue crack advancing direction is 1-2 mm, and the length perpendicular to the fatigue crack advancing direction is 1.8-2.7 mm.

According to another embodiment of the present invention, in step 1) and step 3), before the laser emitter emits the laser beam of the first wavelength, the control system controls the first linear light shaping unit to move horizontally into the optical path; in step 2), the laser Before the transmitter emits the second wavelength laser beam, the control system controls the second linear light shaping unit and the third linear light shaping unit to move horizontally into the optical path; the first wavelength laser beam in the step 1) and step 3) is a Gaussian laser beam , the laser beam of the first wavelength is modulated by the first linear light shaping unit into a rectangular spot D incident on the straight line segment of the fatigue crack, the width of the rectangular spot D in the direction of fatigue crack advancement is 1-2 mm, perpendicular to the direction of advancement The length of the laser beam is 2-3mm; the second wavelength laser beam in the step 2) is a Gaussian laser beam, and the first split laser beam is modulated into a rectangular spot C incident on the fatigue crack curve segment by the second linear light shaping unit , the other split laser beam is also modulated into a rectangular spot C incident on the fatigue crack curve segment by the third linear light shaping unit, and the width of the rectangular spot C in the fatigue crack advancing direction is 1-2mm, perpendicular to The length of the fatigue crack in the forward direction is 1.8-2.7 mm.

Beneficial effect

The laser cladding repair equipment for gear tooth surface fatigue cracks involved in this application uses the control system to detect the shape of fatigue cracks in real time, and the multi-functional lens is coated with a film layer, which can basically completely transmit the first wavelength laser beam, semi-reflective The semi-transparent second-wavelength laser beam adopts different laser processing parameters for the straight line section and the curved section of the fatigue crack, which effectively guarantees the welding quality of the entire fatigue crack, high welding efficiency, uniform grain structure in the cladding area, and effective Improved overall repair quality for fatigue cracks.

Description of drawings

Figure 1 is a schematic diagram of the laser cladding repair equipment and gear tooth surface fatigue crack structure of the present application;

Figure 2 is a schematic diagram of the energy distribution of a circular Gaussian spot;

Fig. 3 is a schematic diagram of energy distribution of a linear rectangular spot;

Figure 4 (a) is a schematic diagram of the first laser light path of the present application; (b) is a schematic diagram of the second laser light path of the present application; (c) is a schematic diagram of the third laser light path of the present application.

In the figure,

1, laser generator; 2, control system; 3, first wavelength laser beam; 4, second wavelength laser beam; 5, multifunctional lens; 6, film layer; 7, reflector; 8, split laser beam; , another split laser beam; 10, the powder feeding channel; 11, the first linear light shaping unit; 12, the second linear light shaping unit; 13, the third linear shaping unit; 14, the fatigue crack of the tooth surface of the gear.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations. Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

As an emerging surface modification technology, laser cladding is the most widely used in gear repair. Compared with traditional repair methods, laser cladding has the advantages of small heat-affected zone and high metallurgical bonding. The quality of gear tooth surface fatigue crack repair depends on the welding quality of the cladding layer. There are many factors that affect the welding quality of the cladding layer. Considering the above aspects, only when the above parameters match each other can a cladding layer with excellent welding performance be obtained.

Embodiment one

Referring to Fig. 1-4(a), an embodiment of the present invention provides a laser cladding repair equipment for gear tooth surface fatigue cracks, the fatigue cracks are basically straight line segments and curved segments, and the laser cladding repair equipment includes:

Laser emitter 1, control system 2, laser emitter 1 emits first wavelength laser 3 and second wavelength laser 4, described control system 2 controls described first wavelength laser 3 in laser emitter 1, described second wavelength Independent switch of the laser 4; the optical path of the first wavelength laser 3 and the second wavelength laser 4 is provided with a multifunctional lens 5, the surface of the multifunctional lens 5 is coated with a film layer 6, and the first wavelength laser 3. After passing through the multifunctional lens 5, it is emitted vertically downward. After the second wavelength laser 4 passes through the multifunctional lens 5, it is split into two identical laser beams. One split laser beam 8 passes through the multifunctional lens 5 It exits vertically downward, and the other split laser beam 9 passes through the reflector 7 and exits vertically downward. One split laser beam 8 and the other split laser beam 9 are arranged in front and back along the fatigue crack length direction; it also includes a powder feeding channel arranged obliquely 10. The powder feeding channel 10 forms an angle α with the vertical direction, and the powder feeding channel 10 is a pneumatic powder feeding; the first wavelength laser beam 3 emitted vertically, the split laser beam 8 after splitting, and the other split laser beam 9 The first linear light shaping unit 11, the second linear light shaping unit 12, the third linear light shaping unit 13, the first linear light shaping unit 11, the second linear light shaping unit 12, and the third linear light shaping The units 13 are all connected to a displacement drive system (not shown), the displacement drive system is connected to the control system 2, and the displacement drive control system is used to control the first linear light shaping unit 11, the second linear light shaping unit 12, the third linear light shaping unit Horizontal movement of the linear light shaping unit 13.

In this embodiment, the surface of the multifunctional lens 5 is coated with a film layer 6. When the laser emitter 1 emits the first wavelength laser beam 3, the multifunctional lens 5 coated with the film layer 6 basically completely transmits it, and the first wavelength laser beam After the beam 3 passes through the multifunctional lens 5, it exits vertically downward; when the laser transmitter 1 emits the second wavelength laser beam 4, the multifunctional lens 5 coated with the film layer 6 splits the second wavelength laser beam 4 into exactly the same Two split laser beams, one split laser beam 8 exits vertically downwards through the multifunctional mirror 5, and the other split laser beam 9 exits vertically downwards after passing through the reflector 7, and the split laser beam 8 and the other split laser beam Bundles 9 are arranged in front and back along the fatigue crack length direction;

Further, in this embodiment, the first linear light shaping unit 11, the second linear light shaping unit 12, and the third linear light shaping unit 13 can move their positions according to the actual situation, and when it is necessary to modulate the linear rectangular spot, by controlling System 2 is connected to the displacement drive system, and the displacement drive system horizontally moves the first linear light shaping unit 11, the second linear light shaping unit 12, and the third linear light shaping unit 13 into the first wavelength laser beam 3, the split laser beam 8, and the other Below a split laser beam 9, the first linear light shaping unit 11, the second linear light shaping unit 12, and the third linear light shaping unit 13 can modulate the Gaussian spot into a rectangular spot according to actual working conditions, see Fig. 2 and Fig. 3 ; When there is no need to modulate the linear rectangular spot, the displacement drive system horizontally shifts the first linear light shaping unit 11, the second linear light shaping unit 12, and the third linear light shaping unit 13 out of the first wavelength laser 3, the split laser beam 8, and the other A split laser beam 9 below.

According to another aspect of the present invention, a laser cladding repair process for fatigue cracks on gear tooth surfaces is provided, and the repair process specifically includes the following steps:

Step 1), the control system 2 obtains the curvature of the fatigue crack on the gear tooth surface to be repaired, and when the control system detects that the current shape of the fatigue crack is basically a straight line segment, the laser transmitter 1 emits the first wavelength laser beam 3 , the laser power is 1800W-2100W, and the first wavelength laser beam 3 is incident on the straight line segment of the fatigue crack;

Step 2), the control system 2 detects the curvature of the fatigue crack in real time, and when the control system 2 detects that the current shape of the fatigue crack is a curve segment, it selects a laser processing technology that matches the curvature of the current curve segment based on the database, and the laser emitter 1 Turn off the first wavelength laser beam 3 and emit the second wavelength laser beam 4 at the same time, the second wavelength laser beam 4 passes through the multifunctional lens 5 coated with a film and then splits into exactly the same one split laser beam 5 and another split laser beam 6. The laser power of one split laser beam 5 and the other split laser beam 6 is 1500W-1700W, and the one split laser beam 5 and the other split laser beam 6 are incident on the curve segment of the fatigue crack 14;

Step 3), when the control system 2 detects that the current shape of the fatigue crack returns to a basic straight line segment, the laser transmitter 1 turns off the second wavelength laser beam 4 and emits the first wavelength laser beam 3 at the same time, the laser power is 1800W-2100W, the first A laser beam 3 of one wavelength is incident on the straight line segment of the fatigue crack.

Wherein, the database in step 2) realizes the integrated construction of welding process data through pre-offline modeling, and different curvatures of fatigue cracks correspond to different laser powers, laser spots, laser scanning speeds and powder feeding rates.

In this embodiment, since in step 2), when the detected fatigue crack is a curve segment, if the scanning speed is too high, the welding path deviation and welding vibration will be caused, so the laser scanning rate should be appropriately reduced at the curve or corner. After reducing the laser scanning rate, if the higher laser power is still used, the process parameters will not match, resulting in over-burning of the cladding weld, coarse grains, etc. Therefore, for fatigue cracks in the curve section, reduce the welding speed and The laser power can theoretically obtain a cladding layer with better welding quality. On the other hand, in actual operation, if the welding speed and laser power are reduced, the welding efficiency will slow down. At the same time, the slower laser scanning rate will also affect the flow and uniformity of the molten pool. Therefore, modulating the two split laser beams can be The welding efficiency of the curve section is significantly improved, and the simultaneous emission of two beams can improve the uniformity of the molten pool, thereby obtaining good welding quality.

Further, in this implementation, the laser transmitter 1 is a multi-wavelength fiber laser, the gear material is No. 45 carbon structural steel, and the materials contained in the cladding layer alloy powder are C, Cr, B, Si, Ni, Fe, wherein Fe The content is not less than 80%.

In step 1) and step 3), the laser defocus is 0 to -20mm, the scanning speed is 300-600mm/min, the powder feeding rate is 30-50g/min, the laser power is 1800W-2100W, and the powder feeding inclination angle is 30°-60°; in step 2), the laser defocus is 0 to -20mm, the laser scanning rate is 240-480mm/min, the powder feeding rate is 24-40g/min, the laser power is 1500W-1700W, and the The powder inclination angle is 30°-60°.

Since the fatigue crack in step 2) is in the shape of a curve, the laser scanning rate is reduced by 20%, and the corresponding powder feeding rate and laser power are simultaneously reduced, so that a better cladding layer weld can be obtained.

Furthermore, since the reflectivity of the metal material is relatively high, in order to increase the laser absorption rate, the laser can be set to a negative defocus amount.

Further, in order to avoid interference between the powder feeding channel and the laser incident head, the included angle α is set to 30°-60°.

Further, in step 1) and step 3), before the laser transmitter 1 emits the first wavelength laser beam 3, the control system 2 controls the first linear light shaping unit 11 to move out of the optical path horizontally;

In step 2), before the laser transmitter 1 emits the laser beam 4 of the second wavelength, the control system 2 controls the second linear light shaping unit 12 and the third linear light shaping unit 13 to move out of the optical path horizontally;

In the step 1) and step 3), the light spot of the first wavelength laser 3 incident on the straight line segment of the fatigue crack is a Gaussian laser spot A, and the laser spot A is circular with a diameter of 2-3 mm; the step 2 In ), the second wavelength laser 4 is a Gaussian laser beam, and the spot of the first split laser beam 8 and the other split laser beam 9 incident on the fatigue crack curve segment is a Gaussian laser spot B after splitting. The laser spot B is circular in shape with a diameter of 1.8-2.7mm.

In this embodiment, step 1), step 3) the first wavelength laser beam 3, and the two split laser beams in step 2) are Gaussian spot, and Gaussian spot is generally common ellipsoidal heat source distribution, heat source performance The form is high in the middle energy, low in the edge energy, and the energy is Gaussian in distribution. Gaussian spot shaping is relatively simple, see Figure 2. In step 2), since the heat accumulation effect in the fatigue crack curve section is more obvious, in order to make the grain structure at the boundary of the cladding weld more uniform, the Gaussian laser spot diameter in step 2) is compared with that in step 1) The diameter of the Gaussian laser spot is reduced by 10%, and the diameter is about 1.8-2.7mm.

Embodiment two

Referring to FIG. 4( b ), this embodiment is an improvement on the basis of Embodiment 1. For details not involved in this embodiment, please refer to the description in Embodiment 1.

In this embodiment, in step 1) and step 3), before the laser transmitter 1 emits the first wavelength laser beam 3, the control system 2 controls the first linear light shaping unit 11 to move out of the optical path horizontally;

In step 2), before the laser transmitter 1 emits the laser beam 4 of the second wavelength, the control system 2 controls the second linear light shaping unit 12 and the third linear light shaping unit 13 to move horizontally into the optical path;

In the step 1) and step 3), the light spot of the first wavelength laser 3 incident on the straight line segment of the fatigue crack is a Gaussian laser spot, and the laser spot A is circular with a diameter of 2-3 mm; the step 2 In ), the second wavelength laser 4 is a Gaussian laser beam, the first split laser beam 8 is modulated by the second linear light shaping unit 12 into a rectangular spot C incident on the fatigue crack curve segment, and the other split laser beam 9 The third linear light shaping unit 13 is also modulated into a rectangular light spot C incident on the fatigue crack curve segment, the width of the rectangular light spot C in the fatigue crack advancing direction is 1-2mm, and the length perpendicular to the fatigue crack advancing direction 1.8-2.7mm.

In this embodiment, the first wavelength laser beam 3 in step 1) and step 3) is a Gaussian laser spot A, the size of the Gaussian laser spot is circular, the diameter is 2-3mm, the laser shaping is simple, and the cladding weld seam is smooth Good sex.

Due to the complexity of curved welding, in order to obtain better welding performance, the energy distribution of the laser is also high. Therefore, a linear spot with uniform energy distribution is used at the curve, as shown in Figure 3, which can significantly improve the melting of the fatigue crack curve. Uniformity of coating grain structure. In step 2), one split laser beam 8 and the other split laser beam 9 are both rectangular spot C after modulation, and the two parallel linear rectangular spots can improve the fluidity and uniformity of the molten pool in the curve segment, and the obtained cladding weld crystal The uniformity of grain structure is higher and the welding efficiency is maintained. In addition, the length of the rectangular spot C in step 2) is reduced by 10% compared with the diameter of the laser spot A in step 1). The appropriately reduced rectangular spot can significantly reduce the heat accumulation at the weld boundary, thereby further improving the welding quality.

Embodiment three

Referring to FIG. 4(c), this embodiment is an improvement on the basis of Embodiment 1. For details not involved in this embodiment, please refer to the description in Embodiment 1.

In step 1) and step 3), before the laser transmitter 1 emits the first wavelength laser beam 3, the control system 2 controls the first linear light shaping unit 11 to move horizontally into the optical path;

In step 2), before the laser transmitter 1 emits the laser beam 4 of the second wavelength, the control system 2 controls the second linear light shaping unit 12 and the third linear light shaping unit 13 to move horizontally into the optical path;

The first wavelength laser beam 3 in the step 1) and step 3) is a Gaussian laser beam, and the first wavelength laser beam 3 is modulated by the first linear light shaping unit 11 into a rectangular spot D incident on the straight line segment of the fatigue crack, The width of the rectangular spot D in the direction of fatigue crack advancement is 1-2mm, and the length perpendicular to the direction of advancement is 2-3mm; the second wavelength laser beam 4 in the step 2) is a Gaussian laser beam, and the A split laser beam 8 is modulated by the second linear light shaping unit 12 into a rectangular spot C incident on the fatigue crack curve segment, and the other split laser beam 9 is also modulated by the third linear light shaping unit 13 to be incident on the fatigue crack A rectangular light spot C on the curve segment, the width of the rectangular light spot C in the fatigue crack advancing direction is 1-2 mm, and the length perpendicular to the fatigue crack advancing direction is 1.8-2.7 mm.

In this embodiment, the first wavelength laser beam 3 in step 1) and step 3) and one split laser beam 8 and another split laser beam 9 in step 2) are modulated into a rectangular spot, and the cladding of the entire fatigue crack All the paths choose a rectangular spot, which can greatly improve the uniformity of the grain structure of the cladding weld.

The rectangular spot D in step 1) has a width of 1-2mm along the advancing direction of the weld, and a length of 2-3mm perpendicular to the advancing direction of the weld. The rectangular spot C in step 2) is in the advancing direction of the fatigue crack The width of the crack is 1-2mm, and the length perpendicular to the direction of fatigue crack progression is 1.8-2.7mm. This is because, since the heat accumulation effect in the curve section is more obvious, in order to make the grain structure at the boundary of the cladding weld more uniform, the length of the rectangular spot C in step 2) is compared with the length of the rectangular spot C in step 1). The light spot D is reduced by 10%, and the properly reduced rectangular light spot can significantly reduce the heat accumulation at the weld boundary, thereby further improving the welding quality.

Claims (8)

1. A laser cladding repair device for gear tooth surface fatigue cracks is characterized in that: the fatigue crack is in a straight line section and a curve section, and the laser cladding repair equipment comprises:

the laser device comprises a laser transmitter (1) and a control system (2), wherein the laser transmitter (1) transmits a first wavelength laser beam (3) and a second wavelength laser beam (4), and the control system (2) controls independent switching of the first wavelength laser beam (3) and the second wavelength laser beam (4) in the laser transmitter (1); the multifunctional laser fatigue crack device is characterized in that a multifunctional lens (5) is arranged on the optical paths of the first wavelength laser beam (3) and the second wavelength laser beam (4), a film layer (6) is plated on the surface of the multifunctional lens (5), the first wavelength laser beam (3) vertically and downwards exits after penetrating through the multifunctional lens (5), the second wavelength laser beam (4) is split into two identical split laser beams after penetrating through the multifunctional lens (5), one split laser beam (8) vertically and downwards exits after penetrating through the multifunctional lens (5), the other split laser beam (9) vertically and downwards exits after penetrating through a reflecting mirror (7), and the one split laser beam (8) and the other split laser beam (9) are arranged and distributed along the length direction of the fatigue crack (14); the powder feeding device further comprises a powder feeding channel (10) which is obliquely arranged, wherein an included angle alpha is formed between the powder feeding channel (10) and the vertical direction, and the powder feeding channel (10) is pneumatic powder feeding.

2. The laser cladding repair apparatus for gear tooth face fatigue cracks according to claim 1, wherein: the device comprises a first wavelength laser beam (3) which is vertically emitted, a first beam-splitting laser beam (8) and another beam-splitting laser beam (9), wherein a first linear light shaping unit (11), a second linear light shaping unit (12) and a third linear light shaping unit (13) are respectively and independently arranged below the first wavelength laser beam, the first linear light shaping unit (11), the second linear light shaping unit (12) and the third linear light shaping unit (13) are connected to a displacement driving system, the displacement driving system is connected with a control system (2), and the displacement driving control system is used for controlling horizontal movement of the first linear light shaping unit (11), the second linear light shaping unit (12) and the third linear light shaping unit (13).

3. A repair process of a laser cladding repair apparatus for gear tooth surface fatigue crack according to claim 1 or 2, the repair process comprising the steps of;

step 1), a control system (2) obtains the curvature of a gear tooth surface fatigue crack (14) to be repaired, when the control system detects that the current shape of the fatigue crack is a straight line segment, a laser transmitter (1) transmits a first wavelength laser beam (3), the laser power is 1800-2100W, and the first wavelength laser beam (3) is incident on the fatigue crack straight line segment;

step 2), detecting the curvature of the fatigue crack in real time by a control system (2), when the control system (2) detects that the current shape of the fatigue crack is a curve segment, selecting a laser processing technology matched with the curvature of the current curve segment based on a database, closing a first wavelength laser beam (3) by a laser emitter (1) and emitting a second wavelength laser beam (4), and splitting the second wavelength laser beam (4) into a completely same one split laser beam (8) and another split laser beam (9) after passing through a multifunctional lens (5) coated with a film layer, wherein the laser power of the one split laser beam (8) and the other split laser beam (9) is 1500-1700W, and the one split laser beam (8) and the other split laser beam (9) are incident on the curve segment of the fatigue crack (14);

step 3), when the control system (2) detects that the current shape of the fatigue crack is restored to be a straight line segment, the laser transmitter (1) turns off the second wavelength laser beam (4) and transmits the first wavelength laser beam (3), the laser power is 1800-2100W, and the first wavelength laser beam (3) is incident on the fatigue crack (14) straight line segment;

the database in the step 2) realizes welding process data integration through offline modeling in advance, and different curvatures of fatigue cracks correspond to different laser powers, laser spots, laser scanning rates and powder feeding rates.

4. A repair process according to claim 3, wherein: the laser transmitter (1) is an optical fiber laser, the gear material is 45 # carbon structural steel, and the material of cladding layer alloy powder comprises C, cr, B, si, ni, fe, wherein the content of Fe is not less than 80%.

5. The repair process according to claim 3 or 4, wherein: in the step 1) and the step 3), the laser defocusing amount is 0 to-20 mm, the laser scanning speed is 300 to 600mm/min, the powder feeding speed is 30 to 50g/min, and the included angle alpha is 30 to 60 degrees;

in the step 2), the laser defocusing amount is 0 to-100 mm, the laser scanning speed is 240 to 480mm/min, the powder feeding speed is 24 to 40g/min, and the included angle alpha is 30 to 60 degrees.

6. The repair process according to claim 5, wherein: in the steps 1) and 3), before the laser transmitter (1) transmits the first wavelength laser beam (3), the control system (2) controls the first linear light shaping unit (11) to horizontally move out of the light path;

in the step 2), before the laser transmitter (1) emits the laser beam (4) with the second wavelength, the control system (2) controls the second linear light shaping unit (12) and the third linear light shaping unit (13) to horizontally move out of the light path;

the light spot of the first wavelength laser (3) in the step 1) and the step 3) incident on the fatigue crack straight line segment is a Gaussian laser light spot A, and the laser light spot A is round and has a diameter of 2-3mm; in the step 2), the second wavelength laser (4) is a Gaussian laser beam, the light spots of the split laser beam (8) and the other split laser beam (9) incident on the fatigue crack curve section are Gaussian laser light spots B, and the laser light spots B are circular in shape and have diameters of 1.8-2.7mm.

7. The repair process according to claim 5, wherein: in the steps 1) and 3), before the laser transmitter (1) transmits the first wavelength laser beam (3), the control system (2) controls the first linear light shaping unit (11) to horizontally move out of the light path;

in step 2), before the laser transmitter (1) emits the second wavelength laser beam (4), the control system (2) controls the second linear light shaping unit (12) and the third linear light shaping unit (13) to horizontally move into the optical path;

the light spot of the first wavelength laser (3) in the step 1) and the step 3) incident on the straight line section of the fatigue crack is a Gaussian laser light spot A, and the laser light spot A is circular and has a diameter of 2-3mm; in the step 2), the second wavelength laser (4) is a Gaussian laser beam, the one split laser beam (8) is modulated into a rectangular light spot C which is incident on the fatigue crack curve section through a second linear light shaping unit (12), the other split laser beam (9) is also modulated into a rectangular light spot C which is incident on the fatigue crack curve section through a third linear light shaping unit (13), the width of the rectangular light spot C in the fatigue crack advancing direction is 1-2mm, and the length of the rectangular light spot C in the direction perpendicular to the fatigue crack advancing direction is 1.8-2.7mm.

8. The repair process according to claim 5, wherein: in the steps 1) and 3), before the laser transmitter (1) transmits the first wavelength laser beam (3), the control system (2) controls the first linear light shaping unit (11) to horizontally move into the light path;

in step 2), before the laser transmitter (1) emits the second wavelength laser beam (4), the control system (2) controls the second linear light shaping unit (12) and the third linear light shaping unit (13) to horizontally move into the optical path;

the first wavelength laser beam (3) in the step 1) and the step 3) is a Gaussian laser beam, the first wavelength laser beam (3) is modulated into a rectangular light spot D which is incident on a straight line section of the fatigue crack through a first linear light shaping unit (11), the width of the rectangular light spot D in the fatigue crack advancing direction is 1-2mm, and the length of the rectangular light spot D in the direction perpendicular to the advancing direction is 2-3mm; in the step 2), the second wavelength laser beam (4) is a Gaussian laser beam, the one split laser beam (8) is modulated into a rectangular light spot C which is incident on the fatigue crack curve section through a second linear light shaping unit (12), the other split laser beam (9) is also modulated into a rectangular light spot C which is incident on the fatigue crack curve section through a third linear light shaping unit (13), the width of the rectangular light spot C in the fatigue crack advancing direction is 1-2mm, and the length of the rectangular light spot C in the direction perpendicular to the fatigue crack advancing direction is 1.8-2.7mm.

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